OE


The phrase “taken aback” indicates that Mary’s former classmates were surprised by how much her behavior had changed since her school years. Since Mary was “exuberant” and prone to “playful antics,” you can determine that she was outgoing as a child. The missing word describes how Mary behaves now, which you can expect to be the opposite of outgoing. A strong prediction would be “shy” or “quiet.” You can thus quickly rule out (A) gregarious, which means “sociable.” (B) discourteous, which means “impolite,” and (E) scurrilous, which means “offensive” or “insulting,” can both be eliminated as no clues indicate that Mary is now rude. (C) obsequious means “fawning” or “servile,” which is unsupported by the context. (D) reticent, meaning “shy” or “introverted,” provides the correct meaning to complete the sentence.